1. Field of the Invention
This invention generally relates to digital to analog converters, and more specifically, to a converter that interpolates analog reference voltages.
2. Description of Related Art
Input devices including proximity sensor devices (also commonly called touchpads or touch sensor devices) are widely used in a variety of electronic systems. A proximity sensor device typically includes a sensing region, often demarked by a surface, in which the proximity sensor device determines the presence, location and/or motion of one or more input objects. Proximity sensor devices may be used to provide interfaces for the electronic system. For example, proximity sensor devices are often used as input devices for larger computing systems (such as opaque touchpads integrated in, or peripheral to, notebook or desktop computers). Proximity sensor devices are also often used in smaller computing systems (such as touch screens integrated in cellular phones).
In some electronic systems, the input devices are integrated with display screens for displaying information to a user of the system. The electronic systems may include a display driver for selecting reference voltages that determine the grey scale of the individual pixels of the display screen. Typically, the display driver receives or generates a digital data signal that is used by a digital to analog converter to output a specific analog reference voltage. This voltage is applied to a material of the display screen (e.g., liquid crystal) to aid in filtering polarized radiation.